germline mutations in women with familial breast cancer and a relative with haematological malignancy
Résumé
Biallelic inactivation of the gene causes ataxia–telangiectasia (A–T), a complex neurological disease associated with a high risk of leukaemias and lymphomas. Mothers of A–T children, obligate heterozygote mutation carriers, have a breast cancer (BC) relative risk of about 3. The frequency of carriers in BC women with a BC family history has been estimated to be 2.70%. To further our clinical understanding of familial BC and examine whether haematological malignancies are predictive of germline mutation, we estimated the frequency of heterozygote mutation carriers in a series of 122 BC women with a family history of both BC and haematological malignancy and without mutation. The gene screening was performed with a new high throughput method, EMMA (enhanced mismatch mutation analysis). Amongst 28 different variants, eight mutations have been identified in eight patients: two mutations leading to a putative truncated protein and six being likely deleterious mutations. One of the truncating mutations was initially interpreted as a missense mutation, p.Asp2597Tyr, but is actually a splice mutation (c.7789G>T/p.Asp2597_Lys2643>LysfsX3). The estimated frequency of heterozygote mutation carriers in our series is 6.56% (95% CI: 2.16–10.95), a significantly higher figure than that observed in the general population, estimated to be between 0.3 and 0.6%. Although a trend towards an increased frequency of carriers was observed, it was not different from that observed in a population of familial BC women not selected for haematological malignancy as the frequency of carriers was 2.70%, a value situated in the confidence interval of our study.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...